Routine diagnosis of respiratory virus infections caused by type A and B influenza, parainfluenza, respiratory synctial, and adenoviruses has been encumbered by relatively slow tissue culture methodology. Recently developed techniques for rapid viral diagnosis, immunofluorescence (IF), radioimmunoassay (RIA), and enzymeimmunoassay (EIA), all rely upon labeled antibody molecules. These techniques employ two methods of detecting virus, i.e., (1) quantitation by measuring radioactivity or a soluble enzyme reaction product or (2) subjective visual assessment of individual stained cells. The EIA is uniquely versatile in that by altering the enzyme substrate both methods of detecting virus (quantitative or subjective) can be applied using the same reagents. We propose to apply two methodologies, the double antibody labeled EIA and the unlabeled peroxidase-antiperoxidase EIA, to the diagnosis of respiratory viruses. Preliminary results in tissue culture will determine which methodology is more sensitive and whether quantitative or subjective methods for detecting virus provide the most sensitive and easily interpreted results. These results will be confirmed using at least 20 clinical specimens positive for each of the respiratory viruses. Finally, a prospective study consisting of at least 25 positive specimens for each of the viruses mentioned will be conducted. Cells and fluid removed from the site of infection will be used to detect virus directly. Aliquots of the same cells will be used for IF examination and results compared with EIA results. Fluid collected will also be inoculated into tissue culture for early virus detection by EIA as well as detection by routine methods. The purpose of the research is to develop acceptable methods for viral diagnosis that will provide physicians with etiologic information rapidly so that patient care will be influenced by that information.